The Cognitive Effects of the Polyphenol Resveratrol in Young, Healthy Humans: A Review of Six Balanced Crossover, Placebo Controlled, Double Blind Trials

Background: Resveratrol increases cerebral blood flow (CBF) but concomitant improvements to cognitive performance are elusive and may be due to relatively underpowered analyses. Objective: The current study combines the individual cohorts from x6 individual trials to create one larger, more powerful, sample size to assess a variety of cognitive outcomes. Design: All trials were placebo controlled, balanced crossover, double blind designs. The combined demographics resulted in a sample size of N=166 with 112 Females and 54 Males between the ages of 18-35 years. Results: Bonferroni corrected repeated measures ANCOVAs revealed no significant differences on x4 individual cognitive tasks. Paired samples t-tests also showed no effects following collapsing of sub-measures from these tasks into x5 global cognitive measures (Accuracy of attention, Speed of attention, Working memory, Speed of memory, Episodic memory) and the effect sizes were small for all outcomes. Conclusions: The results of this summary paper definitively confirms that 500 mg resveratrol does not acutely improve a wide range of cognitions in healthy, 18-35 year old humans

Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a $Z$ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 $< p_{\textrm{T}} < 100$ GeV and in the pseudorapidity range $2.5 < \eta < 4$. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb$^{-1}$. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb public pages

Study of the B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} decay

The decay $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ is studied in proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV using data corresponding to an integrated luminosity of 5 $\mathrm{fb}^{-1}$ collected by the LHCb experiment. In the $\Lambda_{c}^+ K^{-}$ system, the $\Xi_{c}(2930)^{0}$ state observed at the BaBar and Belle experiments is resolved into two narrower states, $\Xi_{c}(2923)^{0}$ and $\Xi_{c}(2939)^{0}$, whose masses and widths are measured to be $$m(\Xi_{c}(2923)^{0}) = 2924.5 \pm 0.4 \pm 1.1 \,\mathrm{MeV}, \\ m(\Xi_{c}(2939)^{0}) = 2938.5 \pm 0.9 \pm 2.3 \,\mathrm{MeV}, \\ \Gamma(\Xi_{c}(2923)^{0}) = \phantom{000}4.8 \pm 0.9 \pm 1.5 \,\mathrm{MeV},\\ \Gamma(\Xi_{c}(2939)^{0}) = \phantom{00}11.0 \pm 1.9 \pm 7.5 \,\mathrm{MeV},$$ where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt $\Lambda_{c}^{+} K^{-}$ sample. Evidence of a new $\Xi_{c}(2880)^{0}$ state is found with a local significance of $3.8\,\sigma$, whose mass and width are measured to be $2881.8 \pm 3.1 \pm 8.5\,\mathrm{MeV}$ and $12.4 \pm 5.3 \pm 5.8 \,\mathrm{MeV}$, respectively. In addition, evidence of a new decay mode $\Xi_{c}(2790)^{0} \to \Lambda_{c}^{+} K^{-}$ is found with a significance of $3.7\,\sigma$. The relative branching fraction of $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ with respect to the $B^{-} \to D^{+} D^{-} K^{-}$ decay is measured to be $2.36 \pm 0.11 \pm 0.22 \pm 0.25$, where the first uncertainty is statistical, the second systematic and the third originates from the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb public pages

Measurement of the ratios of branching fractions R(D∗)\mathcal{R}(D^{*}) and R(D0)\mathcal{R}(D^{0})

The ratios of branching fractions $\mathcal{R}(D^{*})\equiv\mathcal{B}(\bar{B}\to D^{*}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(\bar{B}\to D^{*}\mu^{-}\bar{\nu}_{\mu})$ and $\mathcal{R}(D^{0})\equiv\mathcal{B}(B^{-}\to D^{0}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(B^{-}\to D^{0}\mu^{-}\bar{\nu}_{\mu})$ are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0 fb${ }^{-1}$ of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode $\tau^{-}\to\mu^{-}\nu_{\tau}\bar{\nu}_{\mu}$. The measured values are $\mathcal{R}(D^{*})=0.281\pm0.018\pm0.024$ and $\mathcal{R}(D^{0})=0.441\pm0.060\pm0.066$, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is $\rho=-0.43$. Results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb public pages

The metabolic, cerebral haemodynamic, and cognitive effects of trans-resveratrol in healthy, young and older humans

The stilbene polyphenol trans-resveratrol has shown to interact with several mechanisms that may serve to preserve or even enhance cognitive function, either directly or indirectly. A small, but growing body of research has found resveratrol is capable of nitric oxide (NO)-mediated increases to cerebral blood flow (CBF), which, in turn, serve to increase access to the neural metabolic substrates (oxygen & glucose). To date, research has found increases in CBF and oxygen extraction resulting from oral resveratrol administration, yet these have not been found in conjunction with improved cognitive performance in young, healthy samples; questioning the CBF mechanism of resveratrol as an appropriate means to enhance cognitive performance. Additionally, it was hypothesized that the CBF effects of resveratrol may provide increased utility in naturally ageing populations, as such cohorts are noted to experience reductions to CBF and neural oxygen metabolism; which, in turn, is an acknowledged contributor of age-related cognition. To link the reduced neural oxygen availability suffered during ageing and subsequent poorer cognitive performance, the current thesis also aimed to test the use of hypoxia as a representative, experimental model for the cognitive ageing process. The purpose of this model was to provide clear and direct evidence that the CBF effects of resveratrol can function to attenuate reductions to cognition imposed via a compromised neural fuel supply. Therefore, the four acute, placebo-controlled, double-blind, crossover investigations of this thesis aimed to assess the efficacy of the resveratrol-mediated CBF effects to engender cognitive enhancement; in both young and older adults. The key findings from this thesis show that there is merit to a hypoxia model of cognitive ageing, evidenced by clear cognitive deficits that are also commonly observed with ageing cohorts. Furthermore, a single dose of resveratrol showed to increase fuel oxidation during cognitive performance when measured via indirect calorimetry. However, resveratrol was unable to provide increases to CBF (when measured by Near-Infrared Spectroscopy) or cognitive performance in hypoxia or in ageing populations. In fact, resveratrol was found to impair cognitive performance in the latter. The results of this thesis therefore do not support the argument that resveratrol can provide CBF-mediated cognitive enhancement in healthy, young or naturally ageing samples

Perseverative cognition and snack choice:an online pilot investigation

Perseverative cognition (PC), consisting of worry and rumination, has been consistently linked to a variety of poorer health outcomes, namely via the worsening of stress-induced health risk behaviours. However, research into PC and unhealthy food choice, a key health behaviour, still remains relatively unexplored. In the current pilot investigation, 284 participants were recruited to take part in an online food choice paradigm before completing the Perseverative Thinking Questionnaire (PTQ) and the Brief State Rumination Inventory (BSRI). As a reduced availability of unhealthy snacks has been shown to improve snack choice, participants were randomly allocated to either an even condition (a 3:3 ratio of ≤99 kcal and ≥199 kcal snacks) or an uneven condition (a 4:2 ratio in favour of ≤99 kcal snacks). It was hypothesized that higher levels of PC may predict greater instances of poorer snack choices across, or even within, this paradigm. Despite an increase availability of lower calorie snacks leading to a healthier snack choice, both state and trait PC measures did not significantly influence snack choice irrespective of this varying availability. Although, marginal trends were found for higher state PC and higher calorie crisp selections. The current pilot therefore adds to the growing literature advocating for the use of behavioural economic tactics to engender healthier food choices, yet further work is needed to unpick the mediating role of PC (and its components) in snack consumption paradigms

Risk factors for momentary loss of control and subsequent abandonment of self-devised dietary restraint plans in adults with weight-loss goals : a behaviour sequence analysis approach

Objective: The current study aims to improve understanding of events leading to lapses of dietary restraint, and to identify pathways to perseverance or abandonment of weight loss efforts in response to lapses. In addition, Behaviour Sequence Analysis (BSA) was also evaluated as an analytical tool in dietary behaviour. Design: A sample of 176 adults who were engaging in self-imposed dietary restraint for weight loss were recruited to participate. Main outcome measures: Participants were instructed to provide a detailed written timeline of an episode where they lapsed in their dietary restraint plan. They were instructed to report their preceding behaviours and internal states, and social and environmental contexts, leading up to and after their lapse in dietary restraint. Results: Lapses in dietary restraint were precipitated by negative internal states in the presence of cues for highly palatable foods. In addition, abandonment of weight loss efforts after lapsing was preceded by dichotomous thinking, whereas perseverance was preceded by a more neutral, flexible interpretation of the lapse in self-control. Conclusion: BSA has identified that neutral evaluation of inevitable lapses in dietary restraint are predictive of continuation with weight loss efforts, highlighting the importance of individual tolerance of lapses in self-regulation

Rumination and worry selectively modulate total calorie consumption within an online, nudge tactic paradigm

Rumination and worry, collectively referred to as perseverative cognition, have been implicated in the increased engagement of several health risk behaviours. The current study aimed to investigate the potential influencing role of these repetitive negative thought cognitions in an online snack paradigm. Participants were randomly assigned to either an even condition (a 3:3 ratio of ≤101 kcal and >201 kcal snacks) or an uneven condition (a 4:2 ratio in favour of ≤101 kcal snacks). Upon the presentation of six images of sweet treats, participants were asked to choose the snack they most wanted to consume "right now", before completing the Ultra-Brief Penn State Worry Questionnaire (UB-PSWQ) and the brief (5-item) Ruminative Response Scale (RRS). The results showed that the reduced availability of higher calorie snacks significantly improved both snack choice and total calorie consumption. However, despite rumination and worry having no influence on the snack type chosen, higher levels of rumination still led to significantly higher overall calorie consumption. Although, contrary to predictions, higher levels of worry conversely led to significantly lower overall calorie consumption. This study adds to the growing work in the role of perseverative cognition and food consumption, which may aid in informing public health strategies. Further exploration is needed to assess whether rumination directly induces unhealthy eating behaviours or simply exacerbates them